Ah yes, this is one of my favorites. I love Kantori's art style, plus I have a soft spot for Tifa.
Wish there was a translated version somewhere, though... It always seemed like the camera flashes was what triggered her BE, which I thought was kinda weird. Either that, or it aroused her to the point of lactating, which in turn made her boobs grow, or maybe there's some sort of reference to the original characters from the Genshiken series (which I haven't seen) that I'm not aware of, I dunno. If I recall, the 3rd entry in that series also had some scenes where the guy takes pictures of her and it seems to have similar effects, though I don't recall any noticeable BE in that one.